A study of 38 COVID-infected pregnant women who underwent magnetic resonance imaging (MRI) in Austria found an elevated rate of fetal and placental abnormalities.
In the study, published late last week in The Lancet Regional Health, Medical University of Vienna researchers examined fetal and placental development in 38 pregnant women who tested positive for SARS-CoV-2 and 38 matched, uninfected pregnant women from July 2020 to July 2022. MRIs were performed 83 days, on average, after a positive test.
Twenty-one infections were caused by pre-Omicron SARS-CoV-2 variants (ie, wild-type, Alpha, or Delta), and 18 were Omicron infections. The women were 19 to 36 weeks' pregnant (average, 28 weeks) at MRI.
More lobular, thickened placentas
Globular, or jelly-like, placentas were observed in 30% of women infected pre-Omicron and 27.8% in the Omicron group, while controls had none. Globular placentas can carry a risk of intrauterine growth restriction (UGR, or impeded fetal growth), pre-eclampsia (dangerously high blood pressure during pregnancy), and other abnormalities.
Women with pre-Omicron infections had more placental lobulation and hemorrhages than controls (65% vs 40% and 55% vs 10%, respectively), as well as more thickened placentas. UGR was seen in 25% of fetuses in the pre-Omicron group, and three fetuses had organ abnormalities.
The placentas of pregnant women who have been infected with SARS-CoV-2 should be examined as soon as possible after testing positive using prenatal imaging techniques.
Two unvaccinated, Omicron-infected participants (11%) developed placental abnormalities, compared with one of six triple-vaccinated women (17%).
Pregnancy outcome data were available from 79% of infected patients. One patient each developed pre-eclampsia after Omicron infection, delivered via caesarean at 36 weeks' gestation due to UGR after wild-type infection, and miscarried at 19 weeks due to UGR after Alpha infection. All three placentas had highly abnormal shapes, lobulations, and hemorrhages. All other fetuses were born at term.
"The placentas of pregnant women who have been infected with SARS-CoV-2 should be examined as soon as possible after testing positive using prenatal imaging techniques," coauthor Daniela Prayer, MD, said in a Medical University of Vienna press release.